The sealing nut is for use in expediting repair of leaking flanged pipe joints while pipe is in service and under pressure. It is a closed end nut having a circular rib, concentric with thread and vee-shaped in cross section, projecting from the open end of the nut.
Prior art is described in U.S. Pat. Nos. 3,912,307 and 3,924,649 which were issued to the inventor named in this application. The sealing nut described in his patents has a hardened, beveled, projecting portion on its open end which projection is partially receivable in a bolt hole and which causes the rim of the bolt hole to deform when the sealing nut is tightened. The rim of the bolt hole sometimes has a notch which is too deep to be closed by the deformation of the rim by the projecting beveled portion. The improved sealing nut moves the sealing area out away from the rim. Another problem of the earlier sealing nut is that it is limited to a bolt and nut smaller in diameter than the original so that the beveled portion of the sealing nut can partially enter the bolt hole. The improved sealing nut is not subject to this size limitation.